diff --git a/mopro-msm/src/msm/metal_msm/shader/bigint/bigint.metal b/mopro-msm/src/msm/metal_msm/shader/bigint/bigint.metal
index 6827b21..6f6ead5 100644
--- a/mopro-msm/src/msm/metal_msm/shader/bigint/bigint.metal
+++ b/mopro-msm/src/msm/metal_msm/shader/bigint/bigint.metal
@@ -1,4 +1,5 @@
 // source: https://github.com/geometryxyz/msl-secp256k1
+#pragma once
 
 using namespace metal;
 #include "../misc/get_constant.metal"
diff --git a/mopro-msm/src/msm/metal_msm/shader/curve/jacobian.metal b/mopro-msm/src/msm/metal_msm/shader/curve/jacobian.metal
index 74a81f2..adec12e 100644
--- a/mopro-msm/src/msm/metal_msm/shader/curve/jacobian.metal
+++ b/mopro-msm/src/msm/metal_msm/shader/curve/jacobian.metal
@@ -1,5 +1,6 @@
 // source: https://github.com/geometryxyz/msl-secp256k1
 // algorithms: https://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html
+#pragma once
 
 using namespace metal;
 #include <metal_stdlib>
diff --git a/mopro-msm/src/msm/metal_msm/shader/field/ff.metal b/mopro-msm/src/msm/metal_msm/shader/field/ff.metal
index d46bcfb..f56f160 100644
--- a/mopro-msm/src/msm/metal_msm/shader/field/ff.metal
+++ b/mopro-msm/src/msm/metal_msm/shader/field/ff.metal
@@ -1,4 +1,5 @@
 // source: https://github.com/geometryxyz/msl-secp256k1
+#pragma once
 
 using namespace metal;
 #include <metal_stdlib>
diff --git a/mopro-msm/src/msm/metal_msm/shader/misc/get_constant.metal b/mopro-msm/src/msm/metal_msm/shader/misc/get_constant.metal
index 4f6fa49..859838f 100644
--- a/mopro-msm/src/msm/metal_msm/shader/misc/get_constant.metal
+++ b/mopro-msm/src/msm/metal_msm/shader/misc/get_constant.metal
@@ -1,3 +1,5 @@
+#pragma once
+
 using namespace metal;
 #include <metal_stdlib>
 #include "../constants.metal"
diff --git a/mopro-msm/src/msm/metal_msm/shader/misc/types.metal b/mopro-msm/src/msm/metal_msm/shader/misc/types.metal
index 539b769..8bc7409 100644
--- a/mopro-msm/src/msm/metal_msm/shader/misc/types.metal
+++ b/mopro-msm/src/msm/metal_msm/shader/misc/types.metal
@@ -1,3 +1,5 @@
+#pragma once
+
 using namespace metal;
 #include <metal_stdlib>
 
diff --git a/mopro-msm/src/msm/metal_msm/shader/mont_backend/mont.metal b/mopro-msm/src/msm/metal_msm/shader/mont_backend/mont.metal
index 721e7d7..3e2eddd 100644
--- a/mopro-msm/src/msm/metal_msm/shader/mont_backend/mont.metal
+++ b/mopro-msm/src/msm/metal_msm/shader/mont_backend/mont.metal
@@ -1,4 +1,5 @@
 // adapted from: https://github.com/geometryxyz/msl-secp256k1
+#pragma once
 
 using namespace metal;
 #include <metal_stdlib>